To provide a manufacturing process capable of forming at a low temperature an inorganic oxide semiconductor layer on an inorganic oxide porous excellent in conversion efficiency by using a resin substrate, and to enable manufacturing a photoelectric conversion electrode and a photoelectric conversion cell using the inorganic oxide semiconductor layer.

An ultrasonic welding processing is performed by bringing a horn which transmits vibration energy in contact with an ultrasonic vibrator into intimate contact with an inorganic oxide particle layer with a mean particle diameter of not less than 5 and not more than 500 nm formed on a transparent electrode surface.